Solve using economics formulas

3. Find the present worth of an equipment that has a first cost today of $150,000, an annual operating cost of $60,000, and a salvage value of 20% of the first cost after 5 years; these estimates being in future dollars. Assume the interest rate is 10% per year and that inflation has averaged 7% per year. Solve with inflation (a) not accounted for, and (b) accounted for. (Ans. [a] $-358,821, [b] $-325,630 )